Methods Suitable for Optimizing Linehaul Operations

1. A method suitable for optimizing a linehaul operation comprising jobs and tractors, the method comprising the steps of: (a) providing at least one assignment algorithm designed to solve an assignment problem; (b) providing at least one heuristic, wherein the at least one heuristic includes a heuristic to find all possible optimum solution combinations by grouping jobs and tractors; (c) combining the at least one heuristic with the at least one assignment algorithm to solve the scheduling problem, the combining step comprising the following acts: (i) identifying at least one equivalent assignment solution to an instantaneous assignment problem using the at least one assignment algorithm; and (ii) using the at least one heuristic to select one assignment solution from the at least one equivalent assignment solution such that the selected one assignment solution reduces the cost of at least one other instantaneous assignment solution.

2. The method as recited in claim 1 , wherein the combining step further comprises the act of finding all possible solutions to the instantaneous assignment problem using the at least one assignment algorithm.

3. The method as recited in claim 1 , wherein the combining step further comprises the act of finding a subset of all possible solutions to the instantaneous assignment problem using the at least one assignment algorithm.

4. The method as recited in claim 1 , further comprising an iterating step wherein the selection of a first assignment solution obtained by using the at least one heuristic at a first iteration improves the quality of a second assignment solution achieved at a second iteration in relative comparison to the quality of a third assignment solution obtained as a result of the application of the assignment algorithm without the use of the at least one heuristic.

5. The method as recited in claim 4 , further comprising the act of making a leg assignment at an iteration whereby a unit is routed over at least two legs.

6. The method as recited in claim 5 , wherein the unit is a trailer.

7. The method as recited in claim 5 , wherein the unit is a container.

8. The method as recited in claim 5 , wherein the unit is a car load.

9. The method as recited in claim 5 , wherein the act of making a leg assignment is made for an owner-operator tractor.

10. The method as recited in claim 5 , wherein the act of making a leg assignment is made for a broker tractor.

11. The method as recited in claim 1 , wherein the at least one heuristic includes a routing heuristic.

12. The method as recited in claim 4 , further comprising the act of making a reassignment at each iteration whereby a unit is moved from one time period to another time period.

13. The method as recited in claim 12 , wherein the unit is a trailer.

14. The method as recited in claim 12 , wherein the unit is a container.

15. The method as recited in claim 12 , wherein the unit is a car load.

16. The method as recited in claim 12 , wherein the act of making a reassignment is made by an owner-operator tractor.

17. The method as recited in claim 12 , wherein the act of making a reassignment is made by a broker tractor.

18. The method as recited in claim 1 , wherein the at least one heuristic includes a scheduling heuristic.

19. The method as recited in claim 1 , wherein the at least one assignment algorithm includes the Hungarian Assignment algorithm.

20. The method as recited in claim 1 , wherein the at least one assignment algorithm includes the revised Hungarian Assignment algorithm.

21. The method as recited in claim 1 , wherein the at least one assignment algorithm includes an assignment algorithm which is not the Hungarian Assignment algorithm.

22. The method as recited in claim 1 , wherein the at least one heuristic includes a heuristic to determine the preferred optimum solution in such a way that company tractors and owner-operators tractors end up at the preferred locations thereby lowering the operating cost for the next iteration and for the next day.